Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
sang trong » lang trong, mang trong, nang trong
quang lua » quang cua, quang tuan, quang xuan
lua sang » luc sang, bua sang, cua sang
trong va » trong van, trong ca, trong cac
toan ban » van ban
va toan » van toan, bai toan, tap toan

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((chieu sang) or (chieu sach)) - tinh quang lua sang trong va toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((chieu sang) OR (chieu sach)) - tinh quang lua sang trong va toan ban.
• Adding a wildcard symbol may retrieve word variants: doc ((chieu sang) or (chieu sach)) - tinh quang lua sang trong va toan ban*.